Vulcain rocket engine. View of a Vulcain rocket motor of the type designed for the Ariane 5 launcher. A single Vulcain is used for the first stage of the Ariane 5, its 900 kN (kilonewton) thrust at sea level being supplemented by solid boosters. Vulcain uses liquid hydrogen (LH2) as a fuel, with liquid oxygen (LOX) as oxidiser. At launch, the motor consumes 225kg of LOX and 36kg of LH2 every second. Steering is performed by gimballing the motor up to 6 degrees from vertical with fine control by two vernier motors (long cylinder on side of nozzle). Photographed at the SEP factory at Vernon, France.